Figure 4. Trans-scleral electrophoresis of linear DNA larger than 200 bp

A 230 bp PCR product (lane A) is obstructed by sclera. Lane B is the same 230 bp DNA fragment unimpeded. Lane C is a DNA ladder ranging from 200 to 10 kb unimpeded. Lane D is a DNA ladder obstructed by sclera. Lane E is the same DNA ladder obstructed with a nitrocellulose 0.45 μm filter. Lane F is the same DNA ladder unimpeded. Lanes A, B, and C were run on one gel, and lanes D, E, and F were run on a second gel. The same conditions as in Figure 2 were employed. The data indicate that a 230-bp fragment of DNA passed through the sclera only minimally impeded (compare lanes A and B). Several fragments of a DNA ladder passed through the sclera (lane D) but had slower migration rates than the unimpeded samples. Lanes C, E, and F were loaded with the Gene Choice DNA ladder-1 (now known as HyperLadder I, Catalog number BIO-33025; Bioline USA Inc., Canton, MA).